\section{Findings: Julia vs. Fortran MWRI Runs}
\label{sec:findings}

\subsection{Julia MWRI workflow}
\begin{itemize}
    \item \textbf{Command}: \texttt{bash scripts/run\_mwri\_radiance\_checks.sh}
    \item \textbf{Status}: completed both radiance statistics and NAM analysis legs.
    \item \textbf{Outputs}: JSON metrics at \texttt{results/mwri\_regional\_case\_diag\_rads/cris\_stats\_latest.json} and \texttt{results/mwri\_regional\_case\_nam\_geofix/analysis\_metrics.json}, plus binary state/increment dumps.
    \item \textbf{Outstanding issues}: ecCodes still reports ``Cannot find sub-centre~3'' for NESDIS descriptors, meaning the MTIASI (centre~7/subcentre~3) tables are absent from \texttt{deps/eccodes\_overrides}; radiance sampling proceeds but geolocation fidelity remains at risk.
    \item \textbf{Observation usage}: 96\,100 wind observations assimilated; ATMS/MHS/CrIS subsets sampled (50 profiles each).
\end{itemize}

\subsection{Fortran MWRI workflow}
\begin{itemize}
    \item \textbf{Command}: \texttt{/home/docker/GSI/comGSIv3.7\_EnKFv1.3-mwri/test/check\_gsi\_regional\_results.sh}
    \item \textbf{Status}: all required diagnostics present; cycle~2025091400 validated.  The latest run log lacked the completion string, but runtime stdout confirms successful termination.
    \item \textbf{Artefact sizes}: key diagnostic files range from 24\,656\,B (ATMS subsets) to 8.5\,MB (conventional statistics), providing a baseline for parity checks once Julia emits matching records.
    \item \textbf{Fit statistics}: first-iteration rows available for \texttt{fit\_p1}, \texttt{fit\_q1}, \texttt{fit\_t1}, and \texttt{fit\_w1}; \texttt{fit\_rad1} lacks populated iterations in the reference run.
\end{itemize}

\subsection{Tutorial workflow gaps}
\begin{itemize}
    \item The Julia tutorial harness \texttt{scripts/shell/run\_and\_check\_julia\_gsi.sh} fails during prerequisite checks because the referenced demo script \texttt{scripts/shell/demos/operational\_gsi\_analysis.jl} is missing from the repository.
    \item As a result, no up-to-date Julia execution path exists for the original \texttt{/home/docker/comgsi/tutorial/...} case, preventing direct comparison with the legacy \texttt{run\_and\_check\_gsi.sh}.
\end{itemize}

\subsection{Outcome summary}
\begin{longtable}{p{0.25\linewidth}p{0.32\linewidth}p{0.32\linewidth}}
\textbf{Aspect} & \textbf{Julia MWRI (2025-10-18)} & \textbf{Fortran MWRI (2025-10-16)} \\
\hline
Driver command & \texttt{scripts/run\_mwri\_radiance\_checks.sh} & \texttt{run\_gsi\_regional.ksh} + \texttt{check\_gsi\_regional\_results.sh} \\
Completion status & Completed; warnings about missing NESDIS sequences & Completed; all diagnostics present \\
Wind usage & 96\,100 assimilated winds & Comparable counts in \texttt{diag\_conv\_*} (\(\approx 8.5\)~MB files) \\
Radiance sampling & ATMS/MHS/CrIS subsets decoded; geolocation relies on fallback keys & Full \texttt{diag\_*} radiance diagnostics (>0.8~MB per instrument) \\
Known gaps & Need centre~7/subcentre~3 tables; tutorial harness stale & Latest run log missing completion string; otherwise clean \\
\end{longtable}
